In existing approaches to millimeter wave (mmW) based imaging, an array of optical fibers carrying the up-converted mmW signal may be arranged to mimic an array of antennas capturing the mmW radiation from the scene. The optical beams from the fibers may then be allowed to propagate in free space, and interfere to form an optical image corresponding to the mmW scene on a CCD array. Ideally, each pixel of the CCD receives optical beams from all the fibers. The drawback to this approach is that it does not readily provide a way to obtain three-dimensional (3D) images.